Cheese is widely used by the consumer in many forms. For example, cheese itself is consumed as an end product, but also cheese or cheese flavoring material may be in a dried form or contained in salad dressings, dips, sauces and the like. Due to the wide consumer acceptance of cheese flavoring materials, there is a great demand for such products.
It is known to make a cheese flavoring material by digesting a medium only a portion of which is natural cheese. In U.S. Pat. No. 3,789,182, a powdered cheese flavoring material is provided by treating a cheese and fat blend with an esterase; combining the enzyme treated blend with a protein material (whey, buttermilk, skim milk, soy protein and the like) and drying the combined material. In U.S. Pat. No. 3,765,905, a medium containing protein, carbohydrate and natural cheese is fermented with certain organisms. The product of the fermentation may be spray dried. In U.S. Pat. No. 4,595,594, in a preliminary step a medium composed of young cheese is partially digested by lipase and a neutral protease; cream is added; and the medium which is now a blend of cheese, enzymes and cream is fermented to a product having an intensified cheese flavor.
The present invention relates to use of a coagulase enzyme at very high levels to effect proteolysis in cheese. Until recently, the calf gastric enzyme, rennin, was used almost exclusively to clot or coagulate milk as the first step in commercial cheese making. However, during the decade 1962-1972 there developed a shortage of calf stomachs and cheese makers resorted to rennet substitutes. There are now on the market safe and suitable milk-clotting (coagulase) enzymes. Rennet and the other coagulases now on the market clot fresh milk at a pH 6.2-6.8. At these pH levels, the proteolytic activity of coagulase is extremely low. Coagulase can contribute to the proteolysis of cheese during curing because of the lower pH of cheese. However, cheesemakers have generally limited the amount of coagulase used to only the amount needed to coagulate the milk because of the adverse effects of high levels of coagulase on cheese quality and flavor. When cheese curd or cheese is fermented with only a protease enzyme source, it has been the experience of cheesemakers that the product is bitter. Such experience is disclosed in U.S. Pat. No. 4,595,594. In that patent, it was reported that when cheese curd or cheese was fermented with only a neutral protease as an enzyme source, the product was bitter.
Surprisingly, it has now been found that it is possible to make a non-bitter cheese product by the fermentation of cheese with certain proteases.